Combustion mechanism and model free kinetics of different origin coal samples: Thermal analysis approach
Combustion mechanism and model free kinetics of different origin coal samples: Thermal analysis approach
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DOI：
10.1016/j.energy.2020.117905
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发表时间：
2020-08-01
期刊：
影响因子：
9
通讯作者：
Gokalp, Iskender
中科院分区：
文献类型：
--
作者：
Jayaraman, Kandasamy;Kok, Mustafa Versan;Gokalp, Iskender
采用热重-质谱联用技术对5种不同来源的煤样的热解和燃烧特性进行了表征。将样品在空气气氛中以10、20和30摄氏度/分钟的加热速率在25至900摄氏度的温度下加热。（初始、峰值、燃尽）、反应间隔、质量损失率、灰分残留物、点火和燃烧性能，计算煤样品的着火燃烧指数和反应性，并估计相关的加热速率效应。反应性低的煤具有较高的转化峰温度和较低的着火指数和反应性。煤样品的反应性在2.31和7.84 × 10（2）（1/min）之间变化。主要挥发性和燃烧产物（H-2，CH 4，H2O，CO，CO2，C6 H6，COS，SO2）释放相应的TG和温度估计使用在线3D测量MS的基础上，他们的相对强度和相关性。采用Ozawa-Flynn-Wall（OFW）和Kissinger-Akahira-Sunose（KAS）模型自由动力学方法分别计算了煤的活化能，OFW和KAS模型自由动力学方法计算的活化能分别为44.6 - 75.1kJ/mol和50.5- 96.6kJ/mol。动力学常数的估计进行了比较，发现一致的燃烧性能参数。(C)2020爱思唯尔有限公司保留所有权利。
Five coal samples from different origins are characterized for their pyrolysis and combustion features using coupled thermogravimetry - mass spectrometry (TG-MS). The samples are heated at temperatures ranging from 25 to 900 degrees C in air atmosphere under heating rates of 10, 20, and 30 degrees C/min. The characteristic temperatures (initial, peak, burn out), reaction intervals, mass loss rate, ash residues, ignition and combustion performances, an ignition-combustion index and the reactivities of the coal samples are calculated and the associated heating rate effects are estimated. The less reactive coal exhibits higher peak temperature in conversion and low value of ignition index and reactivity. The reactivity of the coal samples varied in between 2.31 and 7.84 x10(2) (1/min). The main volatile and combustion products (H-2, CH4, H2O, CO, CO2, C6H6, COS, SO2) release for the corresponding TG and temperatures are estimated using online 3D measurements of MS based on their relative intensities and relevancy. Ozawa-Flynn-Wall (OFW) and Kissinger-Akahira-Sunose (KAS) type model free kinetic methods are applied to determine the activation energies of the coals which are exhibited in-between 44.6 - 75.1 kJ/mol and 50.5-96.6 kJ/mol using OFW and KAS methods respectively. The estimated kinetic constants are compared and found consistent with combustion performance parameters. (C) 2020 Elsevier Ltd. All rights reserved.